Mystery solved

I was wondering what this plant was, growing so vigorously in the backyard. And unfortunately, I've conveniently forgotten to label all the seeds and roots and whatnot that I've planted in that spot before. At first, I thought this slightly hairy foliage which was growing about an inch a day was some kind of invasive weed that would crowd out my other plants in no time. After hours of searching on the internet looking for some clues, the closest suspects that I got to were the wild violet and the wild primrose. But the foliage patterns and habit of this curious appearance did not quite fit either and the primrose was more common to the UK and Europe, not in the mid-Atlantic area. 

So I gave up and decided to take some pictures, thinking that I would post it on some gardening forum and ask for help. With a closer look, I discovered the surface of a red potato which I had previously buried in early spring. Similar leaves were sprouting from one of the 'eyes' of the potato. Mystery solved - Solanum tuberosum! It was getting a little too close to a neighboring French lavender start so our tuberous friends would have to relocate to make some room. Mental note to self - label all random plantings to avoid future frantic weed ID searching.